1. Field of the Invention
The present invention relates to a paving mixture which is easily produced and has excellent applying property, and a pavement construction method using that, and particularly, to a paving mixture in which temperature condition conventionally required is relaxed and further, blending ratio condition for a recycled aggregate is relaxed, and a pavement construction method using the same.
2. Prior Art
Technologies regarding recycle in pavement field have been conventionally widely investigated for utilization, including methods using generated materials in pavement and by-products from other fields, and some of them are already standardized by outlines. Those technologies include one paving mixture shown in "Outline for Plant Recycle Pavement Technology" in Japan, and the proportion of the recycled mixtures for paving based on the total production of paving mixtures has increased year by year. While usual paving mixtures are produced recently in approximately the same amount, the amount produced of the recycled mixtures has for paving has been increasing year by year reaching to about 30% in 1995. Namely, social requirement for the recycle mixture for pavement is more and more increasing.
As one method for producing such mixture, there is an indirect heating method in which mixing is conducted with heat-exchanging between a recycled aggregate having normal temperature and a new aggregate heated to high temperature. In the indirect heating method, a batch-wise plant is usually used. According to outline thereof, the blending ratio of the recycled aggregate is usually restricted to about 20% or lower in view of limitation in heating temperature of the new aggregate, necessity of maintenance of temperature of the paving mixture at certain level, heat resistance of a drier, and the like. The indirect heating method has problems in the aspects of quality and applying property that sufficient heat exchange is not easily effected and temperature of the mixture tends to lower, applying property at construction site deteriorates following to decrease in temperature, a binder newly added and an original binder included in the recycled aggregate are not surely mixed in easy fashion, and the like. Further, it is difficult to make blending ratio of the recycled aggregate more than 20% with maintaining given temperature of the mixture from the view point of ability of the plant for heating the aggregate. As other production method, there is a method in which mixing property is enhanced by previously heating the recycled aggregate. In this case, however, there are problems that the original binder to be coated on the recycled aggregate is easily degraded by heat and consequently blue smoke tends to be produced in mixing for production, combustion cost is high in comparison with the indirect heating method since the recycled aggregate and new aggregate are heated and consequently atmospheric disadvantage occurs such as generation of a carbon dioxide gas discharged in combustion, and the like.